<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    input[type="search"]::placeholder{
      color: red;
    }
  </style>
</head>
<body>
  <form action="">
    <input type="search" name="" placeholder="查询参数" autocomplete="on" required>
    <input type="file" multiple>
    <input type="submit" value="提交">
  </form>
</body>
</html>